Speculative Evolution Wiki
Speculative Evolution Wiki

Rabbucks are large lagomorphs from the book After Man: A Zoology of the Future written by Dougal Dixon. 50 million AD, in the Posthomic period, they fill in the niches of deer, most antelope, zebras and even giraffes in part.

Evolution of Rabbucks

During the period immediately before and during the rise of humanity the principal large-scale grazers and browsers were the ungulates, the hoofed mammals. They were generally lightly built running animals, able to escape quickly from predators and with teeth particularly suited to cropping leaves and grasses. The ungulates were widely used by man for his own purposes. Cattle and goats were domesticated for milk and meat, sheep were bred for wool and the skins of many were used for leather. Horses and certain other cattle (called oxen, different from the ones mentioned earlier) were harnessed to work for humans and became the classic beasts of burden. By the time mankind became extinct these particular mammals had become so dependent on humans that they could no longer survive.

The deer, the wild ungulates of the temperate latitudes, fared little better. Vast tracts of temperate woodlands had been destroyed to make room for humanity's cities and to provide agricultural land. This interference with their habitat was so intolerable and put such pressure on the deer that their numbers fell to a level from which they never recovered. What then could take their place? A whole ecological niche was vacant with nothing to exploit it. Which creature was best placed to take the initiative?

During humanity's reign a small-scale grazer was present that was so successful it was considered to be a pest. The rabbit was so seriously destructive of human crops, that humans made numerous attempts to control it and even attempted to exterminate it. Yet no matter what actions he took he never succeeded in getting rid of it completely. After humankind's disappearance, the rabbit's versatility and short breeding cycle enabled it to develop successfully into a number of separate forms. The most successful, the rabbuck, Ungulagus spp., now occupies the niche left by many of the ungulates.

The development of the foot from the large springboard structure of the rabbit to the light, two-toed hoof of the rabbuck was crucial to its evolution. The three principal stages are shown here, although not to scale, from rabbit to hopping rabbuck to running rabbuck. (From left to right: rabbit, hopping rabbuck and running rabbuck)

To begin with the rabbuck changed little from its rabbit ancestors excepting for size. In an environment totally devoid of large, hoofed grazing animals the rabbit was left with no major grazing competitors and quickly evolved to occupy the position they once held. The early rabbucks, Macrolagus spp., retained the hopping gait of their forebears and developed

Several species of hopping rabbuck, Macrolagus spp., still survive. This evolutionary older group consists largely of woodland animals that feed on the leaves and shoots of trees.

strong hind legs for leaping. However, although jumping was ideal for moving around the open grasslands, their traditional habitat, it was not the best method for the confined spaces of the forest, and a more fundamental change had to take place. Several species of this earlier line still exist, but their place has largely been taken by the running forms of rabbuck that more closely resemble the deer of earlier times.

The hopping rabbuck moves in a bounding motion (a, b, c, d) reminiscent of its rabbit ancestors.

The second major development took place some 10 million AD. As well as developing rapidly into the size of a deer the rabbucks also began to evolve the

The running form of rabbuck, Ungulagus spp., moves in a manner similar to that of the ancient deer (e, f, g, h).

typical deer leg and gait. The jumping hind limbs and the generalized forelimbs of the rabbit grew into long-shanked running legs and the feet changed radically. The outer digits atrophied and the second and third toes grew into hoofs, strong enough to bear the animal's weight. This was a highly satisfactory arrangement and this line has now largely replaced the leaping form as the dominant group.

The rabbuck has been so successful that it is found in a wide variety of forms throughout the world - from the tundra and coniferous forests of the far north to the deserts and rainforests of the tropics.

Species of Rabbuck

Common Rabbuck (Ungulagus silvicultrix)

The temperate forest and grassland-dwelling common rabbuck of temperate latitudes of the Northern Continent is the archetypal species of the genus Ungulagus. It grows to around 2 meters high and has a dappled coat which camouflages it effectively among the trees. They are normally found in small herds of between 10 and 12 individuals.

Arctic Rabbuck (Ungulagus hirsutus)

Heavily built with rolls of insulating fat, the Arctic rabbuck is found in the far north of the Northern Continent, in the region of the tundra and coniferous forests. It has a thick hairy coat which turns white in the winter.

Desert Rabbuck (Ungulagus flavus):

A much more lightly built creature with long ears and a short, sandy-colored coat, the desert rabbuck stands no more than 1.2 meters high at the shoulder and is found in arid areas throughout Africa and Asia to the south of the temperate belt

Mountain Rabbuck (Ungulagus scandens)

The mountain rabbuck is the smallest and the least common of all rabbuck species and is found along the western mountains of the Northern Continent (eastern Asia). It is adapted to live on a meager diet of poor grasses and herbs.

Strank (Ungulagus virgatus)

Watoo (Ungulagus cento)

Picktooth (Dolabrodon fossor)

Hopping Rabbucks (Macrolagus spp.)

Additionally, an unidentified rabbuck is seen being attacked by night stalkers on an island in Batavia; it is unknown what species this belongs to, or if is a rabbuck at all.

All rabbucks, whether temperate or tropical, retain the dazzling white tail of their rabbit ancestors. It is used as a warning signal when the herd is attacked.